Information providing system, information providing apparatus and method, and information processing apparatus and method

ABSTRACT

The present invention relates to an information providing system, an information providing apparatus and a method thereof, and an information processing apparatus and a method thereof suppressing unauthorized use of the video contents. A stream contents server  3  issues permission information to a data contents server  10 . The data contents server  10  provides the data contents to which the permission information is added to a TV receiver  7 . A data broadcast engine  73  extracts identification information from the stream contents provided by the stream contents provider  1 , and feeds it to the stream contents provider  1  together with the permission information extracted from the data contents. Based on the permission information and the identification information, the stream contents provider  1  judges whether the reference to the stream contents by the data contents be permitted, and transmits the result of judgement to the digital TV receiver  7 . The invention can be adapted to a digital broadcast system.

TECHNICAL FIELD

[0001] This invention relates to an information providing system, aninformation providing apparatus and a method, and an informationprocessing apparatus and a method. More particularly, the inventionrelates to an information providing system, an information providingapparatus and a method, and an information processing apparatus and amethod, that prevent unauthorized use of information.

BACKGROUND ART

[0002] Owing to a widespread use of an Internet in recent years, it isallowed to receive data contents through the Internet by connecting avariety kinds of information equipment to the internet.

[0003] By adding, for example., an Internet connection function to adigital TV receiver, it is allowed to receive and display not only thedata contents but also the digital TV signals (stream data) broadcastvia, for example, a satellite by using the digital TV receiver.

[0004] When the Internet connection function is added to the digital TVreceiver, however, the data contents received through the Internet maymake a reference to a program (stream contents) that is on air for TVbroadcast, whereby the data contents can be displayed on a screen and,at the same time, the TV images can be displayed as stream contentsreferred to by the data contents.

[0005] As a result, when there are, for example, conflicting sponsors,i.e., a sponsor A providing data contents and a sponsor B providingstream contents, there may take place such an undesired situation thatthe two contents provided by the conflicting sponsors are simultaneouslydisplayed.

[0006] Further, the copyright of the image contents may be infringed ifpredetermined stream contents (image contents) are intentionallyreferred by the data contents.

DISCLOSURE OF THE INVENTION

[0007] This invention was accomplished in view of such circumstances,and intends to properly use information while suppressing unauthorizeduse of information.

[0008] In an information providing system of the invention:

[0009] a second information providing apparatus issues permissioninformation to a first information providing apparatus for permittingthe reference to the second information based on the first information,and provides the second information to an information processingapparatus while adding thereto identification information foridentifying the second information;

[0010] the first information providing apparatus provides the firstinformation to the information processing apparatus while includingtherein the permission information;

[0011] the information processing apparatus extracts the permissioninformation contained in the first information provided by the firstinformation providing apparatus, extracts the identification informationcontained in the second information provided by the second informationproviding apparatus, and transmits the permission information and theidentification information that are extracted to the second informationproviding apparatus;

[0012] the second information providing apparatus judges whether thereference to the second information based on the first information bepermitted, relying upon the permission information received from theinformation processing apparatus and upon the identificationinformation; and

[0013] the information processing apparatus controls the reference tothe second information based on the first information, relying upon theresult judged by the second information providing apparatus.

[0014] The first information may be the data contents, and the secondinformation may be the stream contents.

[0015] The first information providing apparatus is capable of providingthe first information to the information processing apparatus through anetwork.

[0016] The second information providing apparatus is capable ofproviding the second information to the information processing apparatusby broadcast.

[0017] The permission information can include identification informationfor identifying the second information permitting the reference thereto,a name of the second information permitting the reference thereto, aperiod for permitting the reference, an address of the secondinformation providing apparatus that provides the second informationpermitting the reference thereto, or an address of the first informationproviding apparatus providing the first information that is to bereferred to.

[0018] The permission information can include identification informationfor identifying the second information permitting the reference thereto,a name of the second information permitting the reference thereto, aperiod for permitting the reference, an address of the secondinformation providing apparatus that provides the second informationpermitting the reference thereto, or an address of the first informationproviding apparatus providing the first information that is to bereferred to, in the form of information enciphered by using a secret keyof the second information providing apparatus.

[0019] The identification information for identifying the secondinformation can include an ID for identifying the second information, aname of the second information, or information that varies dependingupon the date and hour for providing the second information.

[0020] The identification information for identifying the secondinformation can be enciphered by a public key of the second informationproviding apparatus.

[0021] The second information providing apparatus can possess a databasefor storing identification information for identifying the secondinformation, a name of the second information, information that variesdepending upon the date and hour for providing the second information,period for providing the second information, or information related tothe first information providing apparatus that is permitting thereference to the second information.

[0022] Information related to the first information providing apparatuspermitting the reference to the second information can include addressinformation of the first information providing apparatus and apermission period for permitting the first information providingapparatus to refer to the second information.

[0023] Provision is further made of a certificate-issuing apparatus forissuing a certificate to at least either the first information providingapparatus or the second information providing apparatus, wherein theinformation processing apparatus obtains the certificate issued by thecertificate-issuing apparatus from the first information providingapparatus or the second information providing apparatus, and controlsthe reference to the second information based on the first informationby utilizing the certificate.

[0024] The certificate of the second information providing apparatus caninclude a public key of the second information providing apparatus.

[0025] The information processing apparatus can further obtain acertificate of the certificate-issuing apparatus to control thereference to the second information based on the first information byutilizing the certificate of the certificate-issuing apparatus inaddition to utilizing the certificate of the first information providingapparatus and the certificate of the second information providingapparatus.

[0026] In an information providing method of the invention:

[0027] a second information providing apparatus issues permissioninformation to a first information providing apparatus for permittingthe reference to the second information based on the first information,and provides the second information to an information processingapparatus while adding thereto an identification information foridentifying the second information;

[0028] the first information providing apparatus provides the firstinformation to the information processing apparatus while includingtherein the permission information;

[0029] the information processing apparatus extracts the permissioninformation contained in the first information provided by the firstinformation providing apparatus, extracts the identification informationcontained in the second information provided by the second informationproviding apparatus, and transmits the permission information that isextracted and the identification information to the second informationproviding apparatus;

[0030] the second information providing apparatus judges whether thereference to the second information based on the first information bepermitted, relying upon the permission information received from theinformation processing apparatus and upon the identificationinformation; and

[0031] the information processing apparatus controls the reference tothe second information based on the first information, relying upon theresult judged by the second information providing apparatus.

[0032] The first information processing apparatus of the presentinvention comprises:

[0033] first receiving means for receiving, from the first informationproviding apparatus, the first information including permissioninformation which is issued from the second information providingapparatus to the first information providing apparatus and permits thereference to the second information based on the first information;

[0034] first extracting means for extracting the permission informationincluded in the first information provided by the first informationproviding apparatus;

[0035] second receiving means for receiving, from the second informationproviding apparatus, the second information to which is addedidentification information for identifying the second information;

[0036] second extracting means for extracting the identificationinformation included in the second information provided by the secondinformation providing apparatus;

[0037] transmission means for transmitting the permission informationextracted by the first extracting means and the identificationinformation extracted by the second extracting means to the secondinformation providing apparatus;

[0038] third receiving means for receiving, from the second informationproviding apparatus, the result of judgement concerning whether thereference to the second information based on the first information bepermitted, relying upon the permission information and theidentification information transmitted by the transmission means; and

[0039] control means for controlling the reference to the secondinformation based on the first information according to the result ofjudgement by the second information providing apparatus received fromthe third receiving means.

[0040] The first information may be the data contents, and the secondinformation may be the stream contents.

[0041] The first receiving means is capable of receiving the firstinformation through a network.

[0042] The second receiving means is capable of receiving the secondinformation that is broadcast.

[0043] The permission information can include identification informationfor identifying the second information permitting the reference thereto,a name of the second information permitting the reference, a period forpermitting the reference, an address of the second information providingapparatus that provides the second information permitting the referencethereto, or an address of the first information providing apparatusproviding the first information that is to be referred to.

[0044] The permission information can include identification informationfor identifying the second information permitting the reference thereto,a name of the second information permitting the reference, a period forpermitting the reference, an address of the second information providingapparatus that provides the second information permitting the referencethereto, or an address of the first information providing apparatusproviding the first information that is to be referred to, in the formof information enciphered by using a secret key of the secondinformation providing apparatus.

[0045] The identification information for identifying the secondinformation can include an ID for identifying the second information, aname of the second information, or information that varies dependingupon the date and hour for providing the second information.

[0046] The identification information for identifying the secondinformation can be enciphered by a public key of the second informationproviding apparatus.

[0047] Provision is further made of obtaining means for obtaining acertificate issued by a certificate-issuing apparatus from at leasteither the first information providing apparatus or the secondinformation providing apparatus, wherein control means controls thereference to the second information based on the first information byutilizing the certificate obtained by the obtaining means.

[0048] The certificate of the second information providing apparatus caninclude a public key of the second information providing apparatus.

[0049] The obtaining means can further obtain a certificate of thecertificate-issuing apparatus, and the control means controls thereference to the second information based on the first information byutilizing the certificate of the certificate-issuing apparatus inaddition to utilizing the certificate of the first information providingapparatus and the certificate of the second information providingapparatus.

[0050] An information processing method of the present inventioncomprises:

[0051] a first receiving step for receiving, from the first informationproviding apparatus, the first information including permissioninformation which is issued from the second information providingapparatus to the first information providing apparatus and permits thereference to the second information based on the first information;

[0052] a first extract step for extracting the permission informationincluded in the first information provided by the first informationproviding apparatus;

[0053] a second receiving step for receiving, from the secondinformation providing apparatus, the second information to which isadded identification information for identifying the second information;

[0054] a second extract step for extracting the identificationinformation included in the second information provided by the secondinformation providing apparatus;

[0055] a transmission step for transmitting the permission informationextracted through a processing at the first extract step and theidentification information extracted through a processing at the secondextract step to the second information providing apparatus;

[0056] a third receiving step for receiving, from the second informationproviding apparatus, the result of judgement concerning whether thereference to the second information based on the first information bepermitted, relying upon the permission information and theidentification information transmitted through a step at thetransmission step; and

[0057] a control step for controlling the reference to the secondinformation based on the first information according to the result ofjudgement by the second information providing apparatus received througha processing at the third receiving step.

[0058] A program in a recording medium of the present inventionincludes:

[0059] a first receiving step for receiving, from the first informationproviding apparatus, the first information including permissioninformation which is issued from the second information providingapparatus to the first information providing apparatus and permits thereference to the second information based on the first information;

[0060] a first extract step for extracting the permission informationincluded in the first information provided by the first informationproviding apparatus;

[0061] a second receiving step for receiving, from the secondinformation providing apparatus, the second information to which isadded identification information for identifying the second information;

[0062] a second extract step for extracting the identificationinformation included in the second information provided by the secondinformation providing apparatus;

[0063] a transmission step for transmitting the permission informationextracted through a processing at the first extract step and theidentification information extracted through a processing at the secondextract step to the second information providing apparatus;

[0064] a third receiving step for receiving, from the second informationproviding apparatus, the result of judgement concerning whether thereference to the second information based on the first information bepermitted, relying upon the permission information and theidentification information transmitted through a processing at thetransmission step; and

[0065] a control step for controlling the reference to the secondinformation based on the first information according to the result ofjudgement by the second information providing apparatus received througha processing at the third receiving step.

[0066] A program of the present invention executes:

[0067] a first receiving step for receiving, from the first informationproviding apparatus, the first information including permissioninformation which is issued from the second information providingapparatus to the first information providing apparatus and permits thereference to the second information based on the first information;

[0068] a first extract step for extracting the permission informationincluded in the first information provided by the first informationproviding apparatus;

[0069] a second receiving step for receiving, from the secondinformation providing apparatus, the second information to which isadded identification information for identifying the second information;

[0070] a second extract step for extracting the identificationinformation included in the second information provided by the secondinformation providing apparatus;

[0071] a transmission step for transmitting the permission informationextracted through a processing at the first extract step and theidentification information extracted through a processing at the secondextract step to the second information providing apparatus;

[0072] a third receiving step for receiving, from the second informationproviding apparatus, the result of judgement concerning whether thereference to the second information based on the first information bepermitted, relying upon the permission information and theidentification information transmitted through a processing at thetransmission step; and

[0073] a control step for controlling the reference to the secondinformation based on the first information according to the result ofjudgement by the second information providing apparatus received througha processing at the third receiving step.

[0074] The first information providing apparatus of the presentinvention comprises:

[0075] obtaining means for obtaining permission information forpermitting the reference to the second information based on the firstinformation from the other information providing apparatuses thatprovide, to the above information processing apparatus, the secondinformation that is to be referred to by the first information; and

[0076] providing means for providing, to the information processingapparatus, the first information inclusive of the permission informationobtained from the obtaining means.

[0077] The first information may be the data contents, and the secondinformation may be the stream contents.

[0078] The first information providing apparatus is capable of providingthe first information to the information processing apparatus through anetwork.

[0079] The second information can be provided to the informationprocessing apparatus by broadcast.

[0080] The permission information can include identification informationfor identifying the second information permitting the reference thereto,a name of the second information permitting the reference thereto, aperiod for permitting the reference, addresses of the other informationproviding apparatuses that provide the second information permitting thereference thereto, or an address of the information providing apparatusproviding the first information that is to be referred to.

[0081] The permission information can include identification informationfor identifying the second information permitting the reference thereto,a name of the second information permitting the reference thereto, aperiod for permitting the reference, addresses of the other informationproviding apparatuses that provide the second information permitting thereference thereto, or an address of the information providing apparatusproviding the first information that is to be referred to, in the formof information enciphered by using secret keys of the other informationproviding apparatuses.

[0082] There can be further provided distribution means for distributingthe certificate received from the certificate-issuing apparatus to theinformation processing apparatuses.

[0083] A first information providing method of the present inventioncomprises:

[0084] an obtaining step for obtaining permission information forpermitting the reference to the second information based on the firstinformation from the other information providing apparatuses thatprovide, to the information processing apparatus, the second informationthat is to be referred to by the first information; and

[0085] a providing step for providing, to the information processingapparatus, the first information inclusive of the permission informationobtained through a processing at the obtaining step.

[0086] A first program in the recording medium of the present inventioncomprises:

[0087] an obtaining step for obtaining permission information forpermitting the reference to the second information based on the firstinformation from the other information providing apparatuses thatprovide, to the information processing apparatus, the second informationthat is to be referred to by the first information; and

[0088] a providing step for providing, to the information processingapparatus, the first information inclusive of the permission informationobtained through a processing at the obtaining step.

[0089] A first program of the present invention executes:

[0090] an obtaining step for obtaining permission information forpermitting the reference to the second information based on the firstinformation from the other information providing apparatuses thatprovide, to the information processing apparatus, the second informationthat is to be referred to by the first information; and

[0091] a providing step for providing, to the information processingapparatus, the first information inclusive of the permission informationobtained through a processing at the obtaining step.

[0092] A second information providing apparatus of the inventioncomprises:

[0093] issuing means for issuing permission information to the otherinformation providing apparatuses for permitting the reference to secondinformation based on the first information;

[0094] providing means for providing the second information to theinformation processing apparatus while adding thereto identificationinformation for identifying the second information;

[0095] receiving means for receiving the permission informationextracted by the information processing apparatus from the firstinformation provided by the other information providing apparatuses andis transmitted, and for receiving the identification informationextracted by the information processing apparatus from the secondinformation provided by the providing means and is transmitted;

[0096] judging means for judging whether the reference to the secondinformation based on the first information be permitted based on thepermission information and the identification information received bythe receiving means; and

[0097] transmission means for transmitting the result judged by thejudging means to the information processing apparatus.

[0098] The first information may be the data contents, and the secondinformation may be the stream contents.

[0099] The providing means is capable of providing the secondinformation to the information processing apparatus by broadcast.

[0100] The permission information can include identification informationfor identifying the second information permitting the reference thereto,a name of the second information permitting the reference thereto, aperiod for permitting the reference, an address of the informationproviding apparatus that provides the second information for permittingthe reference, or addresses of the other information providingapparatuses providing the first information that is to be referred to.

[0101] The permission information can include identification informationfor identifying the second information permitting the reference thereto,a name of the second information permitting the reference thereto, aperiod for permitting the reference, an address of the informationproviding apparatus that provides the second information permitting thereference thereto, or addresses of the other information providingapparatuses providing the first information that is to be referred to,in the form of information enciphered by using a secret key of theinformation providing apparatus.

[0102] The identification information for identifying the secondinformation may include an ID for identifying the second information, aname of the second information or information that varies depending uponthe date and hour for providing the second information.

[0103] The identification information for identifying the secondinformation may have been enciphered by the public key of theinformation providing apparatus.

[0104] There can be further provided a database for storingidentification information for identifying the second information, aname of the second information, information that varies depending uponthe date and hour for providing the second information, a period forproviding the second information or information related to the otherinformation providing apparatuses permitting the reference to the secondinformation.

[0105] Information related to the other information providingapparatuses permitting the reference to the second information mayinclude address information of the other information providingapparatuses and a permission period for permitting the other informationproviding apparatuses to refer to the second information.

[0106] There can be further provided distribution means for distributingthe certificate issued from the certificate-issuing apparatus to theinformation processing apparatus.

[0107] The distribution means may distribute the certificate which alsoincludes the public key of the information providing apparatus.

[0108] A second information providing method of the invention comprises:

[0109] an issuing step for issuing permission information to the otherinformation providing apparatuses for permitting the reference to thesecond information based on the first information;

[0110] a providing step for providing the second information to theinformation processing apparatus while adding thereto identificationinformation for identifying the second information;

[0111] a receiving step for receiving the permission informationextracted by the information processing apparatus from the firstinformation provided by the other information providing apparatuses andis transmitted, and for receiving the identification informationextracted by the information processing apparatus from the secondinformation provided through a processing at the providing step and istransmitted;

[0112] a judging step for judging whether the reference to the secondinformation based on the first information be permitted based on thepermission information and the identification information receivedthrough a processing at the receiving step; and

[0113] a transmission step for transmitting the result judged through aprocessing at the judging step to the information processing apparatus.

[0114] A second program in the recording medium of the inventionincludes:

[0115] an issuing step for issuing permission information to the otherinformation providing apparatuses for permitting the reference to thesecond information based on the first information;

[0116] a providing step for providing the second information to theinformation processing apparatus while adding thereto identificationinformation for identifying the second information;

[0117] a receiving step for receiving the permission informationextracted by the information processing apparatus from the firstinformation provided by the other information providing apparatuses andis transmitted, and for receiving the identification informationextracted by the information processing apparatus from the secondinformation provided through a processing at the providing step and istransmitted;

[0118] a judging step for judging whether the reference to the secondinformation based on the first information be permitted based on thepermission information and the identification information receivedthrough a processing at the receiving step; and

[0119] a transmission step for transmitting the result judged through aprocessing at the judging step to the information processing apparatus.

[0120] A second program of the invention executes:

[0121] an issuing step for issuing permission information to the otherinformation providing apparatuses for permitting the reference to thesecond information based on the first information;

[0122] a providing step for providing the second information to theinformation processing apparatus while adding thereto identificationinformation for identifying the second information;

[0123] a receiving step for receiving the permission informationextracted by the information processing apparatus from the firstinformation provided by the other information providing apparatuses andis transmitted, and for receiving the identification informationextracted by the information processing apparatus from the secondinformation provided through a processing at the providing step and istransmitted;

[0124] a judging step for judging whether the reference to the secondinformation based on the first information be permitted based on thepermission information and the identification information receivedthrough a processing at the receiving step; and

[0125] a transmission step for transmitting the result judged through aprocessing at the judging step to the information processing apparatus.

[0126] In the information providing system and in the informationproviding method of the present invention, the first informationproviding apparatus provides the first information inclusive ofpermission information to the information processing apparatus. Thesecond information providing apparatus provides, to the informationprocessing apparatus, the second information to which is added theidentification information for identifying the second information. Theinformation processing apparatus transmits the permission informationextracted from the first information and the identification informationextracted from the second information to the second informationproviding apparatus. Based upon the permission information and theidentification information received from the information processingapparatus, the second providing apparatus judges whether the referenceto the second information based on the first information be permitted.Relying upon the result judged by the second information providingapparatus, the information processing apparatus controls the referenceto the second information based on the first information.

[0127] In the information processing apparatus and method, in therecording medium and in the program of the present invention, permissioninformation is extracted from the first information provided by thefirst information providing apparatus, and identification information isextracted from the second information provided by the second informationproviding apparatus. The permission information and identificationinformation that are extracted, are transmitted to the secondinformation providing apparatus. The result of judging whether thereference to the second information based on the first information bepermitted is received from the second information providing apparatus,and the reference to the second information based on the firstinformation is controlled according to the result of judgement that isreceived.

[0128] In the first information providing apparatus and method, in therecording medium and in the program of the present invention, thepermission information is obtained from the second information providingapparatus, and the first information inclusive of the permissioninformation that is permitted, is provided to the information processingapparatus.

[0129] In the second information providing apparatus and method, in therecording medium and in the program of the present invention, thepermission information is issued to the other information providingapparatuses, and the second information to which the identificationinformation is added, is provided for the information processingapparatus. Based on the permission information and the identificationinformation received from the information processing apparatus, it isjudged weather the reference to the second information based on thefirst information be permitted, and the result of judgement istransmitted to the information processing apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

[0130]FIG. 1 is a diagram illustrating the constitution of aninformation providing system to which the present invention is applied;

[0131]FIG. 2A is a diagram illustrating a state of displaying the datacontents and the stream contents;

[0132]FIG. 2B is a diagram illustrating a state of displaying the datacontents and the stream contents;

[0133]FIG. 2C is a diagram illustrating a state of displaying the datacontents and the stream contents;

[0134]FIG. 3 is a block diagram illustrating a constitution of a digitalTV receiver of FIG. 1;

[0135]FIG. 4 is a diagram illustrating a constitution with the functionof a TV receiver of FIG. 3 as a center;

[0136]FIG. 5 is a block diagram illustrating a constitution of a streamcontents server of FIG. 1;

[0137]FIG. 6 is a block diagram illustrating a constitution of a datacontents server of FIG. 1;

[0138]FIG. 7 is a diagram illustrating a basic processing of theinformation providing system of FIG. 1;

[0139]FIG. 8 is a flowchart illustrating the processing of the digitalTV receiver of FIG. 1;

[0140]FIG. 9 is a flowchart illustrating the processing of the digitalTV receiver that follows FIG. 8;

[0141]FIG. 10 is a diagram illustrating an example of the data contentsreceived by the digital TV receiver of FIG. 1;

[0142]FIG. 11 is a diagram illustrating the structure of permissioninformation;

[0143]FIG. 12 is a diagram illustrating the structure of streamidentification information;

[0144]FIG. 13 is a flowchart illustrating the processing of the streamcontents server of FIG. 1; and

[0145]FIG. 14 is a view illustrating a database possessed by the streamcontents server of FIG. 1.

BEST MODE FOR CARRYING OUT THE INVENTION

[0146]FIG. 1 illustrates the constitution of an information providingsystem to which the present invention is applied. In the informationproviding system, a stream contents provider 1 includes a broadcastingunit 2 and a stream contents server 3. The broadcasting unit 2 and thestream contents server 3 are illustrated to be separate units forconvenience, but they may be constituted integrally together.

[0147] The broadcasting unit 2 broadcasts the digital data of abroadcasting program (stream contents) from a satellite antenna 4 to thehouseholds through a digital broadcast satellite 5.

[0148] In each household, the digital TV receiver 7 receives the streamcontents through a receiving antenna 6. FIG. 1 shows only one digital TVreceiver 7. In practice, however, a large number of digital TV receiversreceive the stream contents.

[0149] The digital TV receiver 7 is connected to an Internet 8. To theInternet 8 is further connected a data contents server 10 possessed by adata contents provider 9. Accordingly, the digital TV receiver 7receives the data contents provided by the data contents server 10through the Internet 8.

[0150] To the Internet 8 are further connected an authentication server12 in a root authentication station 11 and the stream contents server 3in the stream contents provider 1.

[0151] The authentication server 12 issues respective certificates tothe stream contents provider 1 (stream contents server 3) and to thedigital contents provider 9 (data contents server 10) through theInternet 8. As required, further, the authentication server 12 transmitsits own certificate to the digital TV receiver 7 through the Internet 8.

[0152] In the information providing system, as described above, thedigital TV receiver 7 not only receives and displays by itself thestream contents S broadcast by the broadcasting unit 2 as shown in FIG.2A but also receives and displays by itself the data contents D providedby the data contents server 10 through the Internet 8. When the datacontents D are making a reference to the stream contents S, further, thestream contents S are simultaneously displayed on the same screen as thedata contents data D as shown in FIG. 2B.

[0153]FIG. 3 illustrates the constitution of a hardware of the digitalTV receiver 7. A tuner 41 receives broadcast signals from the digitalbroadcast satellite 5, through the receiving antenna 6, and outputs thereceived signals to a demodulator 42. The demodulator 42 demodulates thesignals received by the tuner 41, and sends the demodulated signals to atransport stream (TS) decoding unit 43.

[0154] The TS decoding unit 43 extracts, from the demodulated signals ofthe transport stream input from the demodulator 42, the video data andthe audio data of a predetermined channel instructed by a CPU 52 througha system bus 47, sends the video data to a video decoding unit 45 andsends the audio data to a audio decoding unit 44.

[0155] The video decoding unit 45 decodes the input video data incompliance with an MPEG2 system, and sends them to an exhibit processingunit 46. The exhibit processing unit 46 synthesizes the video data inputfrom the video decoding unit 45 with the data of data contents fed, asrequired, from the CPU 52 through the system bus 47, and sends them to aCRT 91 (FIG. 4) to display them.

[0156] The audio decoding unit 44 decodes the audio data input from theTS decoding unit 43 and sends them to a speaker 92 (FIG. 4).

[0157] An input/output (I/O) interface 48 feeds an operation signalinput from a remote controller 31 to the CPU 52 through the system bus47.

[0158] The CPU 52 executes a variety of processings according toprograms stored in a ROM 50. A RAM 51 suitably stores programs and datanecessary for the CPU 52 to execute a variety of processings. An NVRAM(non-volatile RAM) 49 suitably stores the data that must be maintainedstored even after the power source of the digital TV receiver 7 has beenturned off. A network interface 53 executes the interface processingrelative to the Internet 8.

[0159]FIG. 4 illustrates the constitution with the function of the TVreceiver 7 as a center. A PID (packet ID) filter 71 feeds, from theinput transport stream to a decoder 81 for AV, a packet including videodata and audio data based on a packet ID. The decoder 81 for AV decodesthe video data that are input, feeds them to a frame memory 82 andstores them. The frame memory 82 stores the picture data of one screeninput from the decoder 81 for AV. The frame memory 82 is further fedwith video data of the data contents fed from a data broadcast engine73, and synthesizes them with the video data fed from the decoder 81 forAV as data of a piece of screen.

[0160] The video data read out from the frame memory 82 are convertedinto video signals through a video synthesizing unit 83, and are outputto a CRT 91 and are displayed.

[0161] The decoder 81 for AV decodes the packets of the input audio dataand sends them to a speaker 92.

[0162] The PID filter 71 extracts packets other than the video data andthe audio data from the input transport stream, and feeds them to asection filter 72. The section filter 72 extracts packets (data contentspackets) of data broadcast from the input packets, and feeds them to thedata broadcast engine 73. To the data broadcast engine 73 are connecteda RAM 74 and an NVRAM 75. The data that must be processed by the databroadcast engine 73 are suitably expanded and stored in the RAM 74. Inthe NVRAM 75 are stored the data that must be stored even after thepower source of the data broadcast engine 73 has been turned off.

[0163] A stream identification information descriptor extract module 76executes a process for extracting the stream identification informationincluded in the stream contents (included as a stream identificationinformation descriptor) A driver 77 for network communication executesthe communication processing through the Internet 8.

[0164] An interpreter 78 interprets and executes the script included inthe data contents. A certificate management module 79 manages acertificate issued by the authentication server 12. A permissioninformation analyzing module 80 analyzes permission information includedin the data contents fed from the data contents server 10.

[0165]FIG. 5 illustrates the constitution of the stream contents server3. In FIG. 5, a CPU (central processing unit) 121 executes a variety ofprocessings according to programs stored in a ROM (read-only memory) 122or according to programs loaded by a storage unit 128 onto a RAM (randomaccess memory) 123. In the RAM 123 are further stored data necessary forthe CPU 121 to execute a variety of processings.

[0166] The CPU 121, ROM 122 and RAM 123 are connected to each otherthrough a bus 124. To the bus 124 is further connected an input/outputinterface 125.

[0167] To the input/output interface 125, there are connected an inputunit 126 including a keyboard, a mouse, etc., an output unit 127including a display which may be a CRT (cathode ray tube) or an LCD(liquid crystal display) and a speaker, a storage unit 128 constitutedby a hard disk or the like, and a communication unit 129 constituted bya modem, a terminal adapter and the like. The communication unit 129executes the communication processing through a network inclusive of theInternet 8.

[0168] As required, further, a drive 130 is connected to theinput/output interface 125. A magnetic disk 141, an optical disk 142, amagnetic-optic disk 143, a semiconductor memory 144 and the like aresuitably mounted thereon, and computer programs read out therefrom are,as required, installed in the storage unit 128.

[0169]FIG. 6 illustrates the constitution of the data contents server10. A CPU 221 or a semiconductor memory 244 constituting the datacontents server 10 is constituted in the same manner as the CPU 121 orthe semiconductor memory 144 in the stream contents server 3 shown inFIG. 5. The blocks of the same names are those blocks having the samefunctions, and their description is not repeated.

[0170] The basic processing of the information providing system will bedescribed next with reference to FIG. 7.

[0171] The CPU 121 in the stream contents server 3 controls thecommunication unit 129 at step S1, makes an access to the authenticationserver 12 in the root authentication station 11 through the Internet 8and requests an issuance of a site certificate. Based on this request,the authentication server 12 issues a site certificate S of the streamcontents server 3 (stream contents provider 1). The site certificate Sincludes a public key corresponding to a secrete key assigned to thestream contents provider 1 (stream contents server 3). The CPU 121 inthe stream contents server 3 receives, at step S, the site certificate Sthrough the communication unit 129, and feeds it to the storage unit 128to store it therein.

[0172] Similarly, the CPU 221 of the data contents server 10 in the datacontents provider 9 makes an access to the authentication server 12 atstep S2 and requests the issuance of a site certificate. Based on thisrequest, the authentication server 12 issues the site certificate D. TheCPU 221 in the data contents server 10 receives the site certificate Dat step S2 through the communication unit 229, and stores it in thestorage unit 228.

[0173] The data contents server 10 requests permission for the referenceat step S3 when it must make a reference to the stream contents providedby the stream contents server 3 in the data contents provided by thedata contents server 10 itself. Being controlled by the CPU 221 in thedata contents server 10, the request is transmitted from thecommunication unit 229 to the stream contents server 3 through theInternet 8.

[0174] Upon receipt of the request through the communication unit 129,the CPU 121 in the stream contents server 3 forms permission information(its details will be described later with reference to FIG. 11). The CPU121 controls the communication unit 129 so as to transmit the permissioninformation to the data contents server 10 through the Internet 8.

[0175] The CPU 221 in the data contents server 10 receives, at step S3,the permission information through the communication unit 229, feeds itto the storage unit 228 and stores it therein.

[0176] Through the above processing, the data contents server 10 isallowed to refer to the stream contents provided by the stream contentsprovider 1 in the data contents provided by the data contents server 10itself.

[0177] The data contents provider 9 pays to the stream contents provider1 for a price for the permission information.

[0178] On the other hand, the user of the TV receiver 7 obtains inadvance the certificates of the data contents provider 9 (data contentsserver 10), stream contents provider 1 (stream contents server 3) androot authentication station 11 (authentication server 12) when thestream contents are referred to by the data contents provided by thedata contents provider 9 and when the user wishes to simultaneouslydisplay (exhibit) them.

[0179] At step S4, therefore, the CPU 52 (data broadcast engine 73) inthe digital TV receiver 7 controls the driver 77 for networkcommunication, makes an access to the stream contents server 3 throughthe Internet 8, and requests to transmit a certificate S possessed bythe stream contents server 3.

[0180] Upon receipt of the request through the communication unit 129,the CPU 121 in the stream contents server 3 reads out the certificate Sthat has been stored in the storage unit 128 in advance, and transmitsit from the communication unit 129 to the digital TV receiver 7 throughthe Internet 8.

[0181] Upon receipt of the site certificate S from the stream contentsserver 3 at step S4, the data broadcast engine 73 in the digital TVreceiver 7 feeds it to the storage unit 128 (certificate managementmodule 79) and stores it therein.

[0182] The site certificate S includes a public key of the streamcontents server 3 (stream contents provider 1).

[0183] At step 5, the data broadcast engine 73 controls the driver 77for network communication, makes an access to the data contents server10 through the Internet 8, and requests the data contents server 10(data contents provider 9) to issue a site certificate.

[0184] Upon receipt of this request through the communication unit 229at step 5, the CPU 221 in the data contents server 10 reads out a sitecertificate D stored in the storage unit 228, and transmits it to thedigital TV receiver 7.

[0185] Upon receipt of the site certificate D from the data contentsserver 10 through the driver 77 for network communication at step S5,the data broadcast engine 73 in the digital TV receiver 7 feeds it tothe certificate management module 79 and stores it therein.

[0186] At step S6, similarly, the data broadcast engine 73 makes anaccess to the authentication server 12 and requests to transmit a rootcertificate R. Based on this request, the authentication server 12 atstep S6 transmits the root certificate R to the digital TV receiver 7.

[0187] Upon receipt of the root certificate R from the authenticationserver 12 at step S6, the data broadcast engine 73 in the digital TVreceiver 7 feeds it to the certificate management module 79 and storesit therein.

[0188] As described above, the digital TV receiver 7 stores, in advance,the site certificate S of the stream contents server 3, the sitecertificate D of the data contents server 10 and the root certificate Rof the authentication server 12. These certificates describe that thesource of issuance is the authentication server 12 (root authenticationstation 11).

[0189] When it is desired to be provided with the data contents providedby the data contents server 10, the data broadcast engine 73 makes anaccess to the data contents server 10 at step S7 and requests theprovision of data contents.

[0190] Upon receipt of this request at step S7, the CPU 221 in the datacontents server 10 reads out the data contents stored in the storageunit 228, and transmits them from the communication unit 129 to thedigital TV receiver 7 through the Internet 8.

[0191] Here, when the data contents being provided are referring to thestream contents provided by the stream contents server 3, the permissioninformation issued from the stream contents server 3 is added to thedata contents.

[0192] Upon receipt of the data contents from the data contents server10 at step S7, the data broadcast engine 73 in the digital TV receiver 7feeds them to the interpreter 78 to interpret and execute them. Then,the data contents are converted into character data, are fed to theframe memory 80 and are stored therein. The data stored in the framememory 80 are fed to the CRT 91 through a video synthesizing unit 83 andare displayed.

[0193] The data contents are also fed to the permission informationanalyzing module 80. The permission information analyzing module 80analyzes the permission information included in the input data contents.As will be described later in detail with reference to FIG. 11, thepermission information includes an ID for identifying a stream ID thathas been permitted. At step S8, the broadcasting unit 2 in the streamcontents provider 1 is broadcasting the stream contents while addingthereto the identification information (in a state of a streamidentification information descriptor). The packets containing thestream identification information descriptor are extracted by the PIDfilter 71 and the section filter 72, and are fed to the data broadcastengine 73. The data broadcast engine 73 feeds the input packets to thestream identification information descriptor extract module 76. Thestream identification information extract module 76 extracts the streamidentification information descriptor from the packets. Being extracted,the stream identification information descriptor serves as the streamidentification information.

[0194] At step S9, the data broadcast engine 73 transmits, to the streamcontents server 3, the permission information extracted from the datacontents received from the data contents server 10 through theprocessing at step S7 and the stream identification informationextracted from the stream contents through the processing at step S8.Namely, the inquiry processing is executed concerning whether thepermission information is warrantable.

[0195] Upon receipt of the inquiry of permission information through thecommunication unit 129 at step S9, the CPU 121 in the stream contentsserver 3 judges whether the permission information is warrantable basedupon the database that has been held.

[0196] At step S10, the CPU 121 in the stream contents server 3transmits the judged results, i.e., transmits the permission informationfor referring to the stream contents, to the digital TV receiver 7through the Internet 8.

[0197] Upon receipt of the result of judgement from the stream contentsserver 3 at step S10, the data broadcast engine 73 in the digital TVreceiver 7 causes the decoder 81 for AV to decode the stream contentsbased on the results of judgement, feeds them to the frame memory 80,and describes them on a field of the same screen as that of thecorresponding data contents.

[0198] This is output to the CRT 91 through the video synthesizing unit83 and is displayed. Thus, the CRT 91 displays on the same screen, asshown in FIG. 2B, a picture describing the data contents D and thestream contents S referred to thereby. That is, the two contents can besimultaneously utilized on the same screen.

[0199] When the judged result of the stream contents server 3 is notpermitting the reference to the stream contents S, the data contents Dalone are displayed as shown in FIG. 2C.

[0200] Among the processings roughly described with reference to FIG. 7,the processing of the digital TV receiver 7 will be described in furtherdetail with reference to FIGS. 8 and 9.

[0201] At step S21, the data broadcast engine 73 controls the driver 77for network communication and makes an access to the data contentsserver 10 based on an SSL (secure sockets layer) through the Internet 8.Then, the data broadcast engine 73 requests the data contents server 10to deliver the data contents.

[0202] Based on this request, the CPU 221 in the data contents server 10reads the data contents from the storage unit 228 and transmits themfrom the communication unit 229 to the digital TV receiver 7 through theInternet 8. Here, as described above, the CPU 221 delivers the datacontents while adding thereto the permission information issued from thestream contents server 3 that is providing the stream contents when thedata contents are referring to the stream contents.

[0203] Thus, the data broadcast engine 73 in the digital TV receiver 7receives the contents data transmitted from the data contents server 10.

[0204]FIG. 10 illustrates an example of data transmitted to the digitalTV receiver 7 from the data contents server 10. In FIG. 10,<certificate> is a permission information tag T which is added whenthere exists permission information. Information in a range surroundedby a solid line in the drawing represents permission information LI. Thepermission information LI has been enciphered with a secrete key of thestream contents provider 1 (stream contents server 3). The permissioninformation LI is issued from the stream contents server 3 to the datacontents server 10 in a state of being enciphered at step S3 in FIG. 7described above.

[0205] In these data, “arib://00a0.4012.123/00” and“arib://00a0.4012.123/01” represent the stream contents SC1 and thestream contents SC2 referred to by the data contents.

[0206]FIG. 11 illustrates a structure of the permission informationissued to the data contents server 10 from the stream contents server 3.In this example, the permission information includes, in the form ofplain texts, information I1 which is an ID for identifying the streampermitted by the stream contents provider 1, information I2 which is thename of the program of the permitted stream, information I3 which is aperiod of permission, information I4 representing a site address of thedata contents provider permitting the reference to the stream (siteaddress of the data contents server 10 in the case of FIG. 7), andinformation I5 representing an address of the stream contents provider(stream contents provider 1 in the case of FIG. 7) that confirms thepermission. The permission information further includes information I6obtained by enciphering the above-mentioned information I1 to I5 with asecrete key possessed by the stream contents provider 1 (stream contentsserver 3).

[0207] The permission information LI of FIG. 10 schematically representsthe information I6 of FIG. 11. Information I1 to I5 of FIG. 11 have notbeen diagramed in FIG. 10.

[0208] At step S22, the permission information analyzing module 80judges whether the data received from the data contents server 10 arehaving a permission information tag T. The permission information tag Tis the <certificate> shown in FIG. 10.

[0209] When the permission information T is not included in the receiveddata, the data contents are not permitted to make a reference to thestream contents without the need of examining other information. This isbecause when there exists the permission information LI, the permissioninformation tag T is necessarily included therein. Therefore, thepermission information tag T that is not included means that thepermission information LI is not included in the received data. In thiscase, the routine proceeds to step S28, and the data broadcast engine 73executes the processing for displaying the data contents only. That is,the data broadcast engine 73 transfers the data contents interpreted andexecuted by the interpreter 78 to the frame memory 82 to describe them,and sends them from the video synthesizing unit 83 to the CRT 91 todisplay them. In this case, therefore, the data contents D only aredisplayed as shown in FIG. 2C. Namely, in this case, it is not allowedto simultaneously use the stream contents.

[0210] When it is judged at step S22 that the received data have thepermission information tag T, the routine proceeds to step S23 where itis judged that the certificate of the specified stream contents(referred to by the data contents) is possessed by the digital TVreceiver 7. In FIG. 10, for example, the stream contents SC1 and thestream contents SC2 have been specified in the data contents. It is,therefore, judged whether a site certificate S of the site (streamcontents server 3 in the example of FIG. 7) providing the two streamcontents has already been registered in the certificate managementmodule 79. When there exists no site certificate S in FIG. 7 of thestream contents site that provides the specified stream contents, it hasnot been permitted to refer to the stream contents. Therefore, theroutine proceeds to step S28, and the processing is executed forexhibiting the data contents D only.

[0211] When it is so judged at step S23 that there has been registered asite certificate S of the stream contents site that provides thespecified stream contents, the routine proceeds to step S24 where thedata broadcast engine 73 controls the certificate management module 79and it is judged if the source of issuing the site certificate D of thedata contents server 10 is the same as the source of issuing the sitecertificate S of the stream contents server 3. Namely, it is judged hereif the source of issuing the site certificate D of the data contentsserver 10 and the source of issuing the site certificate S of the streamcontents server 3 in FIG. 7 are the certificates issued from a commonreliable authentication station. Concretely speaking, the certificatemanagement module 79 has received and registered, in advance, the routecertificate R from the authentication server 12 of the routeauthentication station 11. It is, therefore, judged here if either oneor both of the site certificate D and the site certificate S are theones issued by the source that has issued the route certificate R. Whenat least either the site certificate D or the site certificate S is theone issued by a source different from the source that has issued theroute certificate R, it is probable that the certificate is the forgedone. Therefore, the routine proceeds to step S28 to execute theprocessing for displaying the data contents only.

[0212] When it is judged that the site certificate D and the sitecertificate S are the ones issued from the same reliable authenticationstation, the routine proceeds to step S25 where the data broadcastengine 73 controls the permission information analyzing module 80 todecode the enciphered portion (information I6 in FIG. 11) in thepermission information included in the received data by utilizing thepublic key of the stream contents server 3 included in the sitecertificate S. As described earlier, this information I6 has beenenciphered with the secrete key of the stream contents server 3.Therefore, this information can be decoded with the corresponding publickey. As a result of decoding, there are obtained information I1 to I5shown in FIG. 11.

[0213] At step S26, the permission information analyzing module 80compares the information I1 to I5 obtained by decoding at step S25 withthe information I1 to I5 that have been included in the form of a plaintext in the received data, and judges whether they are the same. Whenthey are not the same, it means that the permission information has beenmanipulated. Therefore, the routine proceeds to step S28 where theprocessing is executed for displaying the data contents only.

[0214] On the other hand, when it is judged that the informationobtained by decoding at step S25 is the same as the information that hasbeen included in the form of a plain text in the received data, it meansthat the permission information has not been manipulated. Therefore, theroutine proceeds to step S27 where the permission information analyzingmodule 80 judges whether the data contents server described in thepermission information is in agreement with the data contents serverthat is now being accessed. As described with reference to FIG. 11, thepermission information includes the address of the data contents serverto which the permission information is issued (site address informationI4 of the data contents provider which permits the reference to thestream in FIG. 11). The permission information analyzing module 80judges whether the address of the data contents server which is nowbeing accessed is in agreement with the site address described in theinformation I4 through the driver 77 for network communication. When thetwo are not in agreement, it is probable that the data contents servernow being accessed is not receiving the issuance of permissioninformation. Therefore, the routine proceeds to step S28 where aprocessing is executed for displaying the data contents only. That is,simultaneous use of the stream contents is inhibited.

[0215] If it is judged at step S27 that the data contents server nowbeing accessed is the contents server described in the information I4,the routine proceeds to step S29 where the data broadcast engine 73obtains the stream identification information descriptor of the streamspecified (referred to) in the received data contents from the broadcastwaves, i.e., from the stream contents. The stream identificationinformation descriptor has been included in the stream contents in anenciphered state.

[0216] That is, the broadcasting unit 2 in the stream contents provider1 adds, for example, the stream identification information of theconstitution shown in FIG. 12 to the stream contents that are to bebroadcast, the stream identification information being enciphered withthe public key of the stream contents provider 1 (broadcasting unit 2and the stream contents server 3), and broadcasts them to the householdsfrom the satellite antenna 4 through the digital broadcast satellite 5.

[0217] The stream identification information descriptor extract module76 in the digital TV receiver 7 extracts the stream identificationinformation descriptor from the stream contents that are input throughthe data broadcast engine 73. The stream contents are transmittedaccording to the format of a transport stream of MPEG2 and, hence, thestream identification information is transmitted in the form of adescriptor being included in a program information table. The streamidentification information descriptor extract module 76 extracts thestream identification information descriptor, and extracts the streamidentification information from the descriptor. As described above, thestream identification information has been enciphered with the publickey of the stream contents provider 1. Accordingly, the digital TVreceiver 7 is not allowed to decode the stream identificationinformation.

[0218] Referring to FIG. 12, the stream identification information isconstituted by information I11 serving as an ID for identifying thestream, information I12 as a program name of the stream, and a magicnumber 113 of the stream enciphered with the public key of the streamcontents provider 1.

[0219] The magic number of the stream is information that variesdepending upon the date and hour of when the stream contents arebroadcast. Even the stream contents having the ID for identifying thesame stream may often be broadcast again on a different day. By suitablyvarying the magic number of the stream depending upon the date and hourof broadcast, therefore, the stream contents received through thedigital TV receiver 7 are recorded in a recording medium to prevent suchan occurrence that the stream contents are referred to many times.

[0220] At step S30, the data broadcast engine 73 makes an access to thedata contents server 10 through the processing at step S21, andtransmits the permission information obtained from the received datacontents and the enciphered stream identification information extractedby the descriptor extract module 76 through the processing at step S29,to the stream contents server 3 from the driver 77 for networktransmission through the Internet 8.

[0221] Thus, the enciphered stream identification information reallytaken out from the stream contents is transmitted to the stream contentsserver 3, preventing such an occurrence that the stream contents oncereceived are repetitively referred to by the digital TV receiver 7.

[0222] As will be described later with reference to the flowchart ofFIG. 13, the stream contents 3 servers judges whether the reference tothe stream contents be permitted based on the permission information andthe enciphered stream identification information transmitted from thedigital TV receiver 7, and notifies the result of judgement as aresponse (steps S61, S62 in FIG. 13).

[0223] At step S31, therefore, the data broadcast engine 73 stands byuntil there is a response from the stream contents server 3. When thereis a response, the data broadcast engine 73 at step S32 receives theresponse from the stream contents server 3.

[0224] At step S33, the data broadcast engine 73 judges whether theresponse received through a processing at step S32 is permitting theexhibit of the stream contents. When it is not permitting the exhibit,the routine proceeds to step S28 where a processing is executed forexhibiting the data contents only.

[0225] When it is judged at step S33 that the response from the streamcontents server 3 is permitting the exhibit of the stream contents, theroutine proceeds to step S34 where the data broadcast engine 73 causesthe decoder 81 for AV to decode the stream contents, feeds them to theframe memory 80, describes them on the same screen as the data contents,and sends them to the CRT 91 through the video synthesizing unit 83 todisplay them. Thus, the data contents D and the stream contents S aresimultaneously displayed on the same screen as shown in, for example,FIG. 2B.

[0226] Next, described below in further detail with reference to aflowchart of FIG. 13 is a processing of the stream contents server 3executed in response to the processing of the digital TV receiver 7.

[0227] At step S51, the CPU 121 in the stream contents server 3 standsby until it receives an access from the digital TV receiver 7. Uponreceipt of the access, the CPU 121 proceeds to step S52 to receive thepermission information and the enciphered stream identificationinformation. The permission information and the enciphered streamidentification information are transmitted from the digital TV receiver7 through a processing at step S30 in FIG. 9.

[0228] Upon receipt of the permission information and the encipheredstream identification information from the communication unit 129through the Internet 8, the stream contents server 3 at step S53 decodesthe permission information with its own public key stored in the storageunit 128. Namely, as shown in FIG. 11, the permission informationincludes information I6 that has been enciphered with the secret key ofthe stream content server 3. The CPU 121 decodes the information I6 withits own public key, and judges at step S54 whether the information I1 toI5 obtained by decoding is in agreement with the information I1 to I5that have been transmitted in advance in the form of a plain text. Whenthey are not in agreement, it means that the permission information hasbeen manipulated. The routine, therefore, proceeds to step S62 where theCPU 121 transmits the information from the communication unit 129 to thedigital TV receiver 7 through the Internet 8 in response to an exhibitNG which expresses that the reference to the stream contents has notbeen permitted.

[0229] When it is judged at step S54 that the information I1 to I5obtained by decoding is in agreement with information I1 to I5 that havebeen transmitted in the form of a plain text, the CPU 121 proceeds tostep S55 and decodes the enciphered stream identification informationwith the secret key of the stream contents server 3. Namely, asdescribed above, the stream identification information transmitted fromthe digital TV receiver 7 is in a state of being enciphered with thepublic key of the stream contents server 3 as shown in FIG. 12, and canbe decoded with a corresponding secret key.

[0230] At step S56, the CPU 121 retrieves a data contents serverpermitting the reference to the stream contents from the permissionmanagement database stored in the storage unit 128 based on the streamidentification information decoded through a processing at step S55.

[0231] That is, referring to FIG. 12, when the stream identificationinformation is decoded, there are obtained an ID for identifying thestream, a program name of the stream and a magic number of the stream.

[0232] On the other hand, a permission confirmation database in thestorage unit 128 is holding permission confirmation information shownin, for example, FIG. 14.

[0233] The information I21 is an ID for identifying the stream andcorresponds to the information I11 which is an ID for identifying thestream in the permission information in FIG. 12. The information I22 isa program name of the stream and corresponds to the information I12which is the program name of the stream of FIG. 12. Further, theinformation I23 is a magic number of the stream and corresponds to theinformation I13 which is the magic number of the stream in FIG. 12.

[0234] The information I24 represents a broadcasting period of thestream, and the information I25 represents a list of sites of the datacontents providers permitting the reference to the stream.

[0235] The information I25 is constituted by those information for eachof the sites including the information I31 representing the site(address) of the data contents provider permitting the reference to thestream and the information I32 representing the permission period.

[0236] The CPU 121 identifies (specifies) the stream contents based onthe information I11 to I13 specified in the stream identificationinformation, and retrieves the identified (specified) stream contentsfrom the information I21 to I23 in the database. The CPU 121 furtherretrieves the data contents provider permitting the reference to thestream contents from the data 125 of the retrieved stream contents.

[0237] At step S57, the CPU 121 judges whether there are one or moredata contents servers that are retrieved at step S56. When one or moredata contents servers are not existing, it means that no reference ispermitted to the stream contents. In this case, therefore, the routineproceeds to step S62 where a transmission processing is executed inresponse to the exhibit NG.

[0238] When there are one or more data contents servers that areretrieved, on the other hand, the routine proceeds to step S58 where theCPU 121 judges whether an address in agreement with the address of thedata contents server described in the permission information is existingin the information I31 which is a list of data content servers retrievedat step S56. When there is no address that is in agreement, it meansthat the data contents provider described in the permission informationis no permitting the stream contents. Therefore, a transmissionprocessing is executed at step S62 in response to the exhibit NG.

[0239] When it is judged at step S58 that an address in agreement withthe address of the data contents server described in the permissioninformation is existing in the database, the routine proceeds to stepS59 where it is judged whether the permission period in the data base isin agreement with the content described in the permission information.Namely, it is judged whether the permission period which is theinformation I32 shown in FIG. 14 is in agreement with the permissionperiod which is the information I3 in the permission information shownin FIG. 11. If the two are not in agreement, it is probable that thepermission information has been altered. In this case, too, therefore,the routine proceeds to step S62, and a transmission processing isexecuted in response to the exhibit NG.

[0240] When the two permission periods are in agreement, the routineproceeds to step S60 where the CPU 121 judges whether the present dateand hour counted by the incorporated timer are within the permittedperiod. When the present date and hour are not within the permittedperiod, reference cannot be made to the object stream contents.Therefore, the routine proceeds to step S62 to execute the transmissionprocessing in response to the exhibit NG.

[0241] When it is judged at step S60 that the present date and hour arewithin the permission period, the CPU 121 executes the transmissionprocessing in response to the exhibit OK. After the processing at stepS61 or S62, the routine returns back to step S51 to repeat thesubsequent processings.

[0242] Based on a response transmitted through a processing at step S61or S62 as described above, the digital TV receiver 7 executes thejudging processing at step S33 in FIG. 9, synthesizes the streamcontents data on the same screen as the contents based on the result ofjudgement, and executes the exhibit processing (processing of step S34)as shown in FIG. 2B or executes the processing (processing of step S28in FIG. 8) for displaying the data contents only but without displayingthe stream contents as shown in FIG. 2C.

[0243] In the foregoing description, the data contents comprisingchiefly the text contents are delivered through the Internet 8 and thestream contents comprising chiefly the picture contents are deliveredthrough the broadcast. The present invention, however, can be appliedeven when both of them are delivered through the Internet 8.

[0244] The above series of processings can also be executed by ahardware as well as by a software. When a series of processings are tobe executed by the software, there may be used a computer in which aprogram constituting the software has been incorporated in a dedicatedhardware, or various programs may be installed in, for example, ageneral-purpose personal computer that is capable of executing a varietyof functions from a network or a recording medium.

[0245] Referring to FIGS. 5 and 6, the recording medium is constitutednot only by a magnetic disk 141, 241 (inclusive of a floppy disk), anoptical disk 142, 242 (inclusive of a CD-ROM (compact disk read-onlymemory), a DVD (a digital versatile disk)), a magnetic-optic disk143,243 (inclusive of an MD (mini-disk)) recording programs, or apackage medium such as of a semiconductor memory 144, 244, but also by aROM 122, 222 recording a program provided to the users in a state ofbeing incorporated in the apparatus in advance, or by a hard diskincluded in the storage unit 128, 228.

[0246] In this specification, steps for describing programs to berecorded into the recording medium include processings that are executedin time series along the order that is described, as well as processingsthat are not necessarily executed in time series but are executed inparallel or individually.

[0247] In this specification, the system stands for the entire equipmentconstituted by a plurality of apparatuses.

INDUSTRIAL APPLICABILITY

[0248] According to the information providing system and informationproviding method of the present invention as described above, the secondinformation providing apparatus issues permission information to thefirst information providing apparatus to permit the reference to thesecond information, and the first information providing apparatusprovides the first information to the information processing apparatuswhile including the permission information therein. The informationprocessing apparatus extracts the identification information from thesecond information provided by the second information providingapparatus, and transmits it to the second information providingapparatus together with the permission information included in the firstinformation. The second information providing apparatus judges whetherthe reference to the second information based on the first informationbe permitted relying upon the permission information and theidentification information received from the information processingapparatus, and the information processing apparatus controls thereference to the second information based on the first informationrelying upon the result of judgement.

[0249] There is thus realized a system which suppresses unauthorized useof the second information neglecting the copyright.

[0250] According to the information processing apparatus and method,recording medium and program of the present invention, permissioninformation is extracted from the first information provided by thefirst information providing apparatus, identification information isextracted from the second information provided by the second informationproviding apparatus, the permission information and identificationinformation that are extracted are transmitted to the second informationproviding apparatus, and reference to the second information based onthe first information is controlled relying upon the above informationand upon the result of judgement transmitted from the second informationproviding apparatus. Therefore, the second information is prevented frombeing output and utilized without authorization.

[0251] According to the first information providing apparatus andmethod, recording medium and program of the present invention,permission information obtained from other information providingapparatuses is included in the first information and is provided to theinformation processing apparatus. Therefore, the first information isprovided to the information processing apparatus while preventing thesecond information from being used without authorization.

[0252] According to the second information providing apparatus andmethod, recording medium and program of the present invention,permission information is issued to the other information providingapparatuses, the second information is provided to the informationprocessing apparatus while adding the identification informationthereto, it is judged whether the reference to the second informationbased on the first information be permitted relying upon the permissioninformation and identification information received from the informationprocessing apparatus, and the result of judgement is transmitted to theinformation processing apparatus. Therefore, the second informationprovided by itself is prevented from being used without authorization.

1. An information providing system comprising: a first informationproviding apparatus for providing first information; a secondinformation providing apparatus for providing second information; and aninformation processing apparatus which utilizes said first informationprovided by said first information providing apparatus, and utilizes thesecond information provided by said second information providingapparatus and is referred to by said first information; wherein saidsecond information providing apparatus issues permission information tosaid first information providing apparatus for permitting the referenceto said second information based on said first information, and providessaid second information to said information processing apparatus whileadding identification information thereto for identifying said secondinformation; said first information providing apparatus provides saidfirst information to said information processing apparatus whileincluding therein said permission information; said informationprocessing apparatus extracts said permission information contained insaid first information provided by said first information providingapparatus, extracts said identification information contained in saidsecond information provided by said second information providingapparatus, and transmits said permission information and saididentification information that are extracted to said second informationproviding apparatus; said second information providing apparatus judgeswhether the reference to said second information based on said firstinformation be permitted, relying upon said permission informationreceived from said information processing apparatus and upon saididentification information; and said information processing apparatuscontrols the reference to said second information based on said firstinformation, relying upon the result judged by said second informationproviding apparatus.
 2. The information providing system according toclaim 1, wherein said first information comprises the data contents, andsaid second information comprises the stream contents.
 3. Theinformation providing system according to claim 1, wherein said firstinformation providing apparatus provides said first information to saidinformation processing apparatus through a network.
 4. The informationproviding system according to claim 1, wherein said second informationproviding apparatus provides said second information to said informationprocessing apparatus by broadcast.
 5. The information providing systemaccording to claim 1, wherein said permission information includesidentification information for identifying said second informationpermitting the reference thereto, a name of the second informationpermitting the reference thereto, a period for permitting the reference,an address of said second information providing apparatus that providessaid second information permitting the reference thereto, or an addressof said first information providing apparatus providing said firstinformation that is to be referred to.
 6. The information providingsystem according to claim 5, wherein said permission informationincludes identification information for identifying said secondinformation permitting the reference thereto, a name of the secondinformation permitting the reference thereto, a period for permittingthe reference, an address of said second information providing apparatusthat provides said second information permitting the reference thereto,or an address of said first information providing apparatus providingsaid first information that is to be referred to in the form ofinformation enciphered by using a secret key of said second informationproviding apparatus.
 7. The information providing system according toclaim 1, wherein the identification information for identifying saidsecond information includes an ID for identifying said secondinformation, a name of said second information, or information thatvaries depending upon the date and hour for providing said secondinformation.
 8. The information providing system according to claim 1,wherein the identification information for identifying said secondinformation has been enciphered by a public key of said secondinformation providing apparatus.
 9. The information providing systemaccording to claim 1, wherein said second information providingapparatus possesses a database for storing an identification informationfor identifying said second information, a name of said secondinformation, information that varies depending upon the date and hourfor providing said second information, a period for providing saidsecond information, or information related to said first informationproviding apparatus that is permitting the reference to said secondinformation.
 10. The information providing system according to claim 9,wherein information related to said first information providingapparatus permitting the reference to said second information includesaddress information of said first information providing apparatus and apermission period for permitting said first information providingapparatus to refer to said second information.
 11. The informationproviding system according to claim 1, further comprising acertificate-issuing apparatus for issuing a certificate to at leasteither said first information providing apparatus or said secondinformation providing apparatus, wherein said information processingapparatus obtains said certificate issued by the certificate-issuingapparatus from said first information providing apparatus or said secondinformation providing apparatus, and controls the reference to saidsecond information based on said first information by utilizing saidcertificate.
 12. The information providing system according to claim 11,wherein said certificate of said second information providing apparatusincludes a public key of said second information providing apparatus.13. The information providing system according to claim 11, wherein saidinformation processing apparatus further obtains a certificate of saidcertificate-issuing apparatus to control the reference to said secondinformation based on said first information by utilizing saidcertificate of said certificate-issuing apparatus in addition toutilizing said certificate of said first information providing apparatusand said certificate of said second information providing apparatus. 14.An information providing method in an information providing systemcomprising: a first information providing apparatus for providing firstinformation; a second information providing apparatus for providingsecond information; and an information processing apparatus whichutilizes said first information provided by said first informationproviding apparatus, and utilizes said second information provided bysaid second information providing apparatus and is referred to by saidfirst information; wherein said second information providing apparatusissues permission information to a first information providing apparatusfor permitting the reference to said second information based on saidfirst information, and provides said second information to saidinformation processing apparatus while adding thereto identificationinformation for identifying said second information; said firstinformation providing apparatus provides said first information to saidinformation processing apparatus while including therein said permissioninformation; said information processing apparatus extracts saidpermission information contained in said first information provided bysaid first information providing apparatus, extracts said identificationinformation contained in said second information provided by said secondinformation providing apparatus, and transmits said permissioninformation and said identification information that are extracted tosaid second information providing apparatus; said second informationproviding apparatus judges whether the reference to said secondinformation based on said first information be permitted, relying uponsaid permission information received from said information processingapparatus and upon said identification information; and said informationprocessing apparatus controls the reference to said second informationbased on said first information, relying upon the result judged by saidsecond information providing apparatus.
 15. An information processingapparatus which utilizes first information provided by a firstinformation providing apparatus, and utilizes second informationprovided by a second information providing apparatus and is referred toby said first information, comprising: first receiving means forreceiving, from said first information providing apparatus, said firstinformation including permission information issued from said secondinformation providing apparatus to said first information providingapparatus and permitting the reference to said second information basedon said first information; first extracting means for extracting saidpermission information included in said first information provided bysaid first information providing apparatus; second receiving means forreceiving, from said second information providing apparatus, said secondinformation to which is added identification information for identifyingsaid second information; second extracting means for extracting saididentification information included in said second information providedby said second information providing apparatus; transmission means fortransmitting said permission information extracted by said firstextracting means and said identification information extracted by saidsecond extracting means to said second information providing apparatus;third receiving means for receiving, from said second informationproviding apparatus, the result of judgement concerning whether thereference to said second information based on said first information bepermitted, relying upon said permission information and saididentification information transmitted by said transmission means; andcontrol means for controlling the reference to said second informationbased on said first information according to the result of judgement bysaid second information providing apparatus received from said thirdreceiving means.
 16. An information processing apparatus according toclaim 15, wherein said first information comprises the data contents,and said second information comprises the stream contents.
 17. Aninformation processing apparatus according to claim 15, wherein saidfirst receiving means receives said first information through a network.18. An information processing apparatus according to claim 15, whereinsaid second receiving means receives said second information that isbroadcast.
 19. An information processing apparatus according to claim15, wherein said permission information includes identificationinformation for identifying said second information permitting thereference thereto, a name of said second information permitting thereference thereto, a period for permitting the reference, an address ofsaid second information providing apparatus that provides said secondinformation permitting the reference thereto, or an address of saidfirst information providing apparatus providing said first informationthat is to be referred to.
 20. An information processing apparatusaccording to claim 19, wherein said permission information includesidentification information for identifying said second informationpermitting the reference thereto, a name of said second informationpermitting the reference thereto, a period for permitting the reference,an address of said second information providing apparatus that providessaid second information permitting the reference thereto, or an addressof said first information providing apparatus providing said firstinformation that is to be referred to, in the form of informationenciphered by using a secret key of said second information providingapparatus.
 21. An information processing apparatus according to claim15, wherein said identification information for identifying said secondinformation includes an ID for identifying said second information, aname of said second information, or information that varies dependingupon the date and hour for providing said second information.
 22. Aninformation processing apparatus according to claim 15, wherein saididentification information for identifying said second information hasbeen enciphered by a public key of said second information providingapparatus.
 23. An information processing apparatus according to claim15, further comprising obtaining means for obtaining a certificateissued by a certificate-issuing apparatus from at least either saidfirst information providing apparatus or said second informationproviding apparatus, wherein said control means controls the referenceto said second information based on said first information by utilizingsaid certificate obtained by said obtaining means.
 24. An informationprocessing apparatus according to claim 23, wherein said certificate ofsaid second information providing apparatus includes a public key ofsaid second information providing apparatus.
 25. An informationprocessing apparatus according to claim 23, wherein said obtaining meansfurther obtains a certificate of said certificate-issuing apparatus, andsaid control means controls the reference to said second informationbased on said first information by utilizing said certificate of saidcertificate-issuing apparatus in addition to utilizing said certificateof said first information providing apparatus and said certificate ofsaid second information providing apparatus.
 26. An informationprocessing method for an information processing apparatus which utilizesfirst information provided by a first information providing apparatus,and utilizes second information provided by a second informationproviding apparatus and is referred to by said first information,comprising: a first receiving step for receiving, from said firstinformation providing apparatus, said first information including apermission information which is issued from said second informationproviding apparatus to said first information providing apparatus andpermits the reference to said second information based on said firstinformation; a first extract step for extracting said permissioninformation included in said first information provided by said firstinformation providing apparatus; a second receiving step for receiving,from said second information providing apparatus, said secondinformation to which is added identification information for identifyingsaid second information; a second extract step for extracting saididentification information included in said second information providedby said second information providing apparatus; a transmission step fortransmitting said permission information extracted through a processingat said first extract step and said identification information extractedthrough a processing at said second extract step to said secondinformation providing apparatus; a third receiving step for receiving,from said second information providing apparatus, the result ofjudgement concerning whether the reference to said second informationbased on said first information be permitted, relying upon saidpermission information and said identification information transmittedthrough a step at said transmission step; and a control step forcontrolling the reference to said second information based on said firstinformation according to the result of judgement by said secondinformation providing apparatus received through a processing at saidthird receiving step.
 27. A recording medium recording a program whichcan be read by a computer and which controls an information processingapparatus which utilizes first information provided by a firstinformation providing apparatus, and utilizes second informationprovided by a second information providing apparatus and is referred toby said first information, said program comprising: a first receivingstep for receiving, from said first information providing apparatus,said first information including permission information which is issuedfrom said second information providing apparatus to said firstinformation providing apparatus and permitting the reference to saidsecond information based on said first information; a first extract stepfor extracting said permission information included in said firstinformation provided by said first information providing apparatus; asecond receiving step for receiving, from said second informationproviding apparatus, said second information to which is addedidentification information for identifying said second information; asecond extract step for extracting said identification informationincluded in said second information provided by said second informationproviding apparatus; a transmission step for transmitting saidpermission information extracted through a processing at said firstextract step and said identification information extracted through aprocessing at said second extract step to said second informationproviding apparatus; a third receiving step for receiving, from saidsecond information providing apparatus, the result of judgementconcerning whether the reference to said second information based onsaid first information be permitted, relying upon said permissioninformation and said identification information transmitted through aprocessing at said transmission step; and a control step for controllingthe reference to said second information based on said first informationaccording to the result of judgement by said second informationproviding apparatus received through a processing at said thirdreceiving step.
 28. A program which executes, by using a computer thatcontrols an information processing apparatus which utilizes firstinformation provided by a first information providing apparatus, andutilizes second information that is provided by a second informationproviding apparatus and is referred to by said first information: afirst receiving step for receiving, from said first informationproviding apparatus, said first information including permissioninformation issued from said second information providing apparatus tosaid first information providing apparatus and permitting the referenceto said second information based on said first information; a firstextract step for extracting said permission information included in saidfirst information provided by said first information providingapparatus; a second receiving step for receiving, from said secondinformation providing apparatus, said second information to which isadded identification information for identifying said secondinformation; a second extract step for extracting said identificationinformation included in said second information provided by said secondinformation providing apparatus; a transmission step for transmittingsaid permission information extracted through a processing at said firstextract step and said identification information extracted through aprocessing at said second extract step to said second informationproviding apparatus; a third receiving step for receiving, from saidsecond information providing apparatus, the result of judgementconcerning whether the reference to said second information based onsaid first information be permitted, relying upon said permissioninformation and said identification information transmitted through aprocessing at said transmission step; and a control step for controllingthe reference to said second information based on said first informationaccording to the result of judgement by said second informationproviding apparatus received through a processing at said thirdreceiving step.
 29. An information providing apparatus for providingfirst information to an information processing apparatus, comprising:obtaining means for obtaining permission information for permitting thereference to said second information based on said first informationfrom the other information processing apparatuses that provide, to saidinformation providing apparatus, said second information that is to bereferred to by said first information; and providing means forproviding, to said information processing apparatus, said firstinformation inclusive of said permission information obtained from saidobtaining means.
 30. An information providing apparatus according toclaim 29, wherein said first information comprises the data contents,and said second information comprises the stream contents.
 31. Aninformation providing apparatus according to claim 29, wherein saidproviding means provides said first information to said informationprocessing apparatus through a network.
 32. An information providingapparatus according to claim 29, wherein said second information isprovided to said information processing apparatus by broadcast.
 33. Aninformation providing apparatus according to claim 29, wherein saidpermission information includes identification information foridentifying said second information permitting the reference thereto, aname of said second information permitting the reference thereto, aperiod for permitting the reference, addresses of the other informationproviding apparatuses that provide said second information permittingthe reference thereto, or an address of said information providingapparatus providing said first information that is to be referred to.34. An information providing apparatus according to claim 33, whereinsaid permission information includes identification information foridentifying said second information permitting the reference thereto, aname of said second information permitting the reference thereto, aperiod for permitting the reference, addresses of the other informationproviding apparatuses that provide said second information forpermitting the reference thereto, or an address of the informationproviding apparatus providing said first information that is to bereferred to, in the form of information enciphered by using secret keysof the other information providing apparatuses.
 35. An informationproviding apparatus according to claim 29, further comprisingdistribution means for distributing the certificate received from thecertificate-issuing apparatus to said information processingapparatuses.
 36. An information providing method for an informationproviding apparatus that provides first information to an informationprocessing apparatus, comprising: an obtaining step for obtainingpermission information for permitting the reference to said secondinformation based on said first information from the other informationproviding apparatuses that provide, to said information processingapparatus, said second information that is to be referred to by saidfirst information; and a providing step for providing, to saidinformation processing apparatus, said first information inclusive ofsaid permission information obtained through a processing at saidobtaining step.
 37. A recording medium recording a program which can beread by a computer and which controls an information providing apparatusthat provides first information to an information processing apparatus,said program comprising: an obtaining step for obtaining permissioninformation for permitting the reference to said second informationbased on said first information from the other information providingapparatuses that provide, to said information providing apparatus, saidsecond information that is to be referred to by said first information;and a providing step for providing, to said information processingapparatus, said first information inclusive of said permissioninformation obtained through a processing at said obtaining step.
 38. Aprogram which executes, by using a computer that controls an informationproviding apparatus which provides first information to an informationprocessing apparatus: an obtaining step for obtaining permissioninformation for permitting the reference to said second informationbased on said first information from the other information providingapparatuses that provide, to said information processing apparatus, saidsecond information that is to be referred to by said first information;and a providing step for providing, to said information processingapparatus, said first information inclusive of said permissioninformation obtained through a processing at said obtaining step.
 39. Aninformation providing apparatus for providing, to an informationprocessing apparatus, second information referred to by firstinformation which is provided by the other information providingapparatuses to said information processing apparatus, comprising:issuing means for issuing permission information to the otherinformation providing apparatuses for permitting the reference to saidsecond information based on said first information; providing means forproviding said second information to said information processingapparatus while adding thereto identification information foridentifying said second information; receiving means for receiving saidpermission information extracted by said information processingapparatus from said first information provided by said other informationproviding apparatuses and is transmitted, and for receiving saididentification information extracted by said information processingapparatus from said second information provided by said providing meansand is transmitted; judging means for judging whether the reference tosaid second information based on said first information be permittedbased on said permission information and said identification informationreceived by said receiving means; and transmission means fortransmitting the result judged by said judging means to said informationprocessing apparatus.
 40. An information providing apparatus accordingto claim 39, wherein said first information comprises the data contents,and said second information comprises the stream contents.
 41. Aninformation providing apparatus according to claim 39, wherein saidproviding means provides said second information to said informationprocessing apparatus by broadcast.
 42. An information providingapparatus according to claim 39, wherein said permission informationincludes identification information for identifying said secondinformation permitting the reference thereto, a name of said secondinformation permitting the reference thereto, a period for permittingthe reference, an address of the information providing apparatus thatprovides said second information permitting the reference thereto, oraddresses of the other information providing apparatuses providing saidfirst information that is to be referred to.
 43. An informationproviding apparatus according to claim 42, wherein said permissioninformation includes an identification information for identifying saidsecond information permitting the reference thereto, a name of saidsecond information permitting the reference thereto, a period forpermitting the reference, an address of said information providingapparatus that provides said second information permitting the referencethereto, or addresses of the other information providing apparatusesproviding said first information that is to be referred to, in the formof information enciphered by using a secret key of said informationproviding apparatus.
 44. An information providing apparatus according toclaim 39, wherein said identification information for identifying saidsecond information includes an ID for identifying said secondinformation, a name of said second information or information thatvaries depending upon the date and hour for providing said secondinformation.
 45. An information providing apparatus according to claim39, wherein said identification information for identifying said secondinformation has been enciphered by the public key of said informationproviding apparatus.
 46. An information providing apparatus according toclaim 39, further comprising a database for storing identificationinformation for identifying said second information, a name of saidsecond information, information that varies depending upon the date andhour for providing said second information, a period for providing saidsecond information or information related to the other informationproviding apparatuses permitting the reference to said secondinformation.
 47. An information providing apparatus according to claim46, wherein information related to the other information providingapparatuses permitting the reference to said second information includesaddress information of the other information providing apparatuses and apermission period for permitting the other information providingapparatuses to refer to said second information.
 48. An informationproviding apparatus according to claim 39, further comprisingdistribution means for distributing the certificate issued from saidcertificate-issuing apparatus to said information processing apparatus.49. An information providing apparatus according to claim 48, whereinsaid distribution means distributes said certificate while includingtherein the public key of said information providing apparatus.
 50. Aninformation providing method for an information providing apparatuswhich provides, to an information processing apparatus, secondinformation that is referred to by first information provided by theother information providing apparatuses to said information processingapparatus, comprising: an issuing step for issuing permissioninformation to the other information providing apparatuses forpermitting the reference to said second information based on said firstinformation; a providing step for providing said second information tosaid information processing apparatus while adding theretoidentification information for identifying said second information; areceiving step for receiving said permission information extracted bysaid information processing apparatus from said first informationprovided by the other information providing apparatuses and istransmitted, and for receiving said identification information extractedby said information processing apparatus from said second informationprovided through a processing at said providing step and is transmitted;a judging step for judging whether the reference to said secondinformation based on said first information be permitted based on saidpermission information and said identification information receivedthrough a processing at said receiving step; and a transmission step fortransmitting the result judged through a processing at said judging stepto said information processing apparatus.
 51. A recording mediumrecording a program which can be read by a computer and which controlsan information providing apparatus which provides, to an informationprocessing apparatus, second information that is referred to by firstinformation provided by the other information providing apparatuses tosaid information processing apparatus, said program comprising: anissuing step for issuing permission information to the other informationproviding apparatuses for permitting the reference to said secondinformation based on said first information; a providing step forproviding said second information to said information processingapparatus while adding thereto identification information foridentifying said second information; a receiving step for receiving saidpermission information extracted by said information processingapparatus from said first information provided by the other informationproviding apparatuses and is transmitted, and for receiving saididentification information extracted by said information processingapparatus from said second information provided through a processing atsaid providing step and is transmitted; a judging step for judgingwhether the reference to said second information based on said firstinformation be permitted based on said permission information and saididentification information received through a processing at saidreceiving step; and a transmission step for transmitting the resultjudged through a processing at said judging step to said informationprocessing apparatus.
 52. A program for executing, by using a computerthat controls an information providing apparatus for providing, to aninformation processing apparatus, second information referred to byfirst information provided by the other information providingapparatuses to said information processing apparatus: an issuing stepfor issuing permission information to the other information providingapparatuses for permitting the reference to said second informationbased on said first information; a providing step for providing saidsecond information to said information processing apparatus while addingthereto identification information for identifying said secondinformation; a receiving step for receiving said permission informationextracted by said information processing apparatus from said firstinformation provided by the other information providing apparatuses andis transmitted, and for receiving said identification informationextracted by said information processing apparatus from said secondinformation provided through a processing at said providing step and istransmitted; a judging step for judging whether the reference to saidsecond information based on said first information be permitted based onsaid permission information and said identification information receivedthrough a processing at said receiving step; and a transmission step fortransmitting the result judged through a processing at said judging stepto said information processing apparatus.